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Daren
My motorhome will not hook up to a shoreline that has ground fault plugs. Trips breaker as soon as hooked up. Works fine at non GF plugs. Any ideas...........
mastercraft
Does your motorhome have a ground fault built in to the shorepower? If so, you cannot run 2 ground faults on the same line.
Daren
QUOTE(Daren @ Apr 28 2007, 09:37 PM) *

My motorhome will not hook up to a shoreline that has ground fault plugs. Trips breaker as soon as hooked up. Works fine at non GF plugs. Any ideas...........

Doe not have GF in shore power line.
mastercraft
Have you asked other motorhomes that have connected to GFCI shore power if they are having a problem? When you hook up to GFCI which breaker trips the one on your coach or the the one at the coach?
Daren
Other people that we travel with are not experiencing the same troubles. The GF trips on the Campground supplied service. Have had this trouble in serveral different locations. Have checked every area of the camper for shorts. Everything works fine as long as the campground is not wired with Ground Fault circuits. More and more campground are wired with GF, including the 30 amp service. Will meet with local camper repair shop this week. Hoping to find someone that has had this problem in the past. Our family purchased this motorhome new in 1991 and have never had troubles before.
mastercraft
It sounds to me that you have a GFCI going bad in the motorhome that might be tripping the shore power. Either that or you have a short somewhere. Have the GFCI's in the coach checked first. Good luck.
gsbogart
I would check to see if your system ground and your system bond are hooked to the same bus bar. In the motorhome I believe they are supposed to be isolated. That is why you have 3 terminals on your 30 amp and 4 on your 50 amp.
Daren
Thanks. Will check that.
John Blue
Daren,

You have a leak in your system someplace. The GFI is used to check current from hot wire 120 volts to ground wire. If current is not the same on each lead then GFI will trip off. The current leak can be very low and trip. Number of ways to run this down. You need to be very carefully as 120 volts can kill you. As little as 10 ma will do the job.

!. Remove power cable from MH then plug in cable at power post and see if cable is bad.

2. Open each ckt. brk one at time and see if that will fix it.

3. If all ckt brks are open and you have a trip, open leads that come into AC power box
to see if that will fix it.

4. If you have a gen set then you will have a tranfer relay. In this box you have wires from outside power and wires from gen set. One set of wires will come off this relay and go to AC power box to feed MH. Open up wires to you see problem drop off them add them back one at the time to see problem zone.

You need to remove power cable at post each time you open or rehook any wires. The trick is to open up the load points one by one to see the fault.

I found one problem due to water in wires under ground. I guess it was a leak.
Daren
Thanks. Have an electrician coming over next week to help test. Must have a short somewhere. He explained how to test each circuit. If I haven't found it by the first of the week, he will come out and help. Did all the simple tests. Power cord tested ok. With all the breakers off it still trips GFI on campground outlet. Cheated this week due to the hot weather. Placed a new cord in the breaker box only to the AC unit. Works great. At least I know the AC wiring is fine.
Daren
gsbogart
QUOTE(Daren @ May 4 2007, 10:20 AM) *

Thanks. Have an electrician coming over next week to help test. Must have a short somewhere. He explained how to test each circuit. If I haven't found it by the first of the week, he will come out and help. Did all the simple tests. Power cord tested ok. With all the breakers off it still trips GFI on campground outlet. Cheated this week due to the hot weather. Placed a new cord in the breaker box only to the AC unit. Works great. At least I know the AC wiring is fine.
Daren

Daren
Have you gotten tothe botom of your problem yet?

As I mentioned before in my post, it is possible that the ground and bond wire are hooked to the same buss bar in your RV. The way you can check that out is to take a continuity reading between the ground leg of your 3 prong plug and the round or bond terminal of the plug. If you get continuity on these two connectors, you have a problem. RV's are not suppose to have a common between these connectors, and if they do, you will trip a ground fault supply.
bigfootford1
If you have a 3 way fridge, check your AC power cord inside the service panel. Your looking for a melted/ disfigured power cord.

Click below to read......

Investigation underway

If you don't see anything, unplug the fridge and try reseting the GFI.

Keep us informed.....

Jim
Dallas Walker
QUOTE(John Blue @ May 2 2007, 10:51 PM) *

Daren,

You have a leak in your system someplace. The GFI is used to check current from hot wire 120 volts to ground wire. If current is not the same on each lead then GFI will trip off. The current leak can be very low and trip. Number of ways to run this down. You need to be very carefully as 120 volts can kill you. As little as 10 ma will do the job.

!. Remove power cable from MH then plug in cable at power post and see if cable is bad.

2. Open each ckt. brk one at time and see if that will fix it.

3. If all ckt brks are open and you have a trip, open leads that come into AC power box
to see if that will fix it.

4. If you have a gen set then you will have a tranfer relay. In this box you have wires from outside power and wires from gen set. One set of wires will come off this relay and go to AC power box to feed MH. Open up wires to you see problem drop off them add them back one at the time to see problem zone.

You need to remove power cable at post each time you open or rehook any wires. The trick is to open up the load points one by one to see the fault.

I found one problem due to water in wires under ground. I guess it was a leak.
Dallas Walker
QUOTE(John Blue @ May 2 2007, 10:51 PM) *

Daren,

You have a leak in your system someplace. The GFI is used to check current from hot wire 120 volts to ground wire. If current is not the same on each lead then GFI will trip off. The current leak can be very low and trip. Number of ways to run this down. You need to be very carefully as 120 volts can kill you. As little as 10 ma will do the job.

!. Remove power cable from MH then plug in cable at power post and see if cable is bad.

2. Open each ckt. brk one at time and see if that will fix it.

3. If all ckt brks are open and you have a trip, open leads that come into AC power box
to see if that will fix it.

4. If you have a gen set then you will have a tranfer relay. In this box you have wires from outside power and wires from gen set. One set of wires will come off this relay and go to AC power box to feed MH. Open up wires to you see problem drop off them add them back one at the time to see problem zone.

You need to remove power cable at post each time you open or rehook any wires. The trick is to open up the load points one by one to see the fault.

I found one problem due to water in wires under ground. I guess it was a leak.


Daren,

Your check list is very informative.

I have checked each item and still have the problem.

When I first plug in to shore power I have a slight imbalance between hot and netural but no measurable current on the ground. When you are refering to bonding vs ground, do you mean that the chassie ground used for the DC circuits and the AC ground should be isolated? I have a wire connected from my AC ground bus to the Chassie ground, when I remove it the external GFI still trips. I'm sooo confused.

Dallas rolleyes.gif
gsbogart
Dallas

It is obvious from your posts that you are not reading or understanding the solution regarding grounding and bonding.
First of all, do not confuse the 12 volt and 120 volt system. They are separate systems, and must remain that way. What we are discussing is the 120 volt system and its wiring schematics. If you have the bond(bare copper wire connected to chassis and the ground from the shore power connected to a common bar in the fuse panel, you will trip a GFI protected circuit. That is because the GFI measures the potential difference between the ground and hot wire of the GFI

Look in your breaker box and see if these wires are connected. The other way I mentioned is to take an ohm meter and check the continuity between the spades on the male plug. With the main breaker off. there should not be any continuity between any of these spades.

If this is too confusing, I suggest you have an electrician look at your system.






QUOTE(Dallas Walker @ Sep 26 2007, 09:34 PM) *

QUOTE(John Blue @ May 2 2007, 10:51 PM) *

Daren,

You have a leak in your system someplace. The GFI is used to check current from hot wire 120 volts to ground wire. If current is not the same on each lead then GFI will trip off. The current leak can be very low and trip. Number of ways to run this down. You need to be very carefully as 120 volts can kill you. As little as 10 ma will do the job.

!. Remove power cable from MH then plug in cable at power post and see if cable is bad.

2. Open each ckt. brk one at time and see if that will fix it.

3. If all ckt brks are open and you have a trip, open leads that come into AC power box
to see if that will fix it.

4. If you have a gen set then you will have a tranfer relay. In this box you have wires from outside power and wires from gen set. One set of wires will come off this relay and go to AC power box to feed MH. Open up wires to you see problem drop off them add them back one at the time to see problem zone.

You need to remove power cable at post each time you open or rehook any wires. The trick is to open up the load points one by one to see the fault.

I found one problem due to water in wires under ground. I guess it was a leak.


Daren,

Your check list is very informative.

I have checked each item and still have the problem.

When I first plug in to shore power I have a slight imbalance between hot and netural but no measurable current on the ground. When you are refering to bonding vs ground, do you mean that the chassie ground used for the DC circuits and the AC ground should be isolated? I have a wire connected from my AC ground bus to the Chassie ground, when I remove it the external GFI still trips. I'm sooo confused.

Dallas rolleyes.gif
John Blue
Daren,

I see you have not found the problem yet. The information from Gsbogart is correct. The ground bond is wrong in one of your panels. If you bond AC power ground to frame and wires were rolled over in power post as soon as you touch the door frame 120 volts will travel down to your feet into ground, not a good thing to happen.

Need to check with a good meter and see if you have a small ckt. leak on one wire some place. As I wrote before take the time to remove wires from load panel (power off first) and then hookup power to post. On 30 amp system you will have three wires. Should be a black (120) white ground and green AC bond. If you do not trip off them wires are OK up to panel.

Remember the problem could be anyplace. If panel is OK then open up each lead to outlets one at the time to see if any are the problem. Someone may have added a wire from green bond to frame in service bay or at gen. set. Lots of places to mess up wiring in a RV unit. Think about the AC inv. unit as well as this unit is under power all the time. It had AC input fuses that you can remove.

We need feed back from you to help. tongue.gif
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